The present invention relates to ion-sensitive electrodes for determining the concentrations of certain mainly cations in electrolytes.
Known ion-senstive electrodes for monovalent cations have several disadvantages; erosion by electrolytes in which the electrodes are placed tends to occur, the maximum temperature at which such electrodes can be used is the boiling point of water and since the electrodes often take the form of glass electrodes with an internal electrolyte they are relatively fragile. In addition known ion-sensitive electrodes sensitive to monovalent cations tend to be unstable with time and temperature. Further the concentrations of certain monovalent cations such as Rb.sup.+, Cs.sup.+ and Li.sup.+ could not formerly be measured at all by electro-analytical techniques using ion-sensitive electrodes. It is expected that at least some of the above disadvantages will be wholly or partly overcome by the present invention.